Sustaining the Saco estuary final report 2015 Sustaining the Saco estuary final report 2015 Project Leaders Christine B. Feurt, Ph.D. Pamela A. Morgan, Ph.D. University of New England and University of New England Wells National Estuarine Research Reserve Tel: (207) 602-2227 Tel: (207) 602-2834 Email: [email protected] Email: [email protected] Project Team University of New England Mark Adams, Ph.D. Noah Perlut, Ph.D. Anna Bass, Ph.D. Michele Steen-Adams, Ph.D. Carrie Byron, Ph.D. James Sulikowski, Ph.D. Michael Daley, Ph.D. Stephan I. Zeeman, Ph.D. Michael Esty Wells National Estuarine Research Reserve Jacob Aman Jeremy Miller Michele Dionne, Ph.D. Kristin Wilson, Ph.D. This research is part of Maine’s Sustainability Solutions Initiative, a program of the Senator George J. Mitchell Center, which is supported by National Science Foundation award EPS-0904155 to Maine EPSCoR at the University of Maine. Report Editing and Design: Waterview Consulting CONTENTS CHAPTER 1 INTRODUCTION: Why Is the Saco Estuary an Ideal Living Laboratory for Sustainability Science?.......................1 by Christine B. Feurt and Pamela A. Morgan CHAPTER 2 RECOGNIZING AND ENGAGING THE StewardsHIP NETWORK: Actively Working to Sustain the Saco Estuary .......7 by Christine B. Feurt CHAPTER 3 PLANTS OF THE SACO EstuarY: Tidal Marshes............17 by Pam Morgan CHAPTER 4 BENTHIC MACROINVertebrates OF THE SACO EstuarY: Tidal Flats and Low Marsh Habitats .......................29 by Anna L. Bass CHAPTER 5 FISH OF THE SACO EstuarY: River Channel and Tidal Marshes ........................................39 by Kayla Smith, Kristin Wilson, James Sulikowski, and Jacob Aman CHAPTER 6 BIRD COMMUNITY OF THE SACO EstuarY: Tidal Marshes ...57 by Noah Perlut CHAPTER 7 FOOD WEB OF THE SACO Estuary’S Tidal MARSHES . .69 by Carrie Byron CHAPTER 8 LAND USE AND LAND COVER ALONG THE SACO Estuary’S SHORELINE .........................................81 by Mark Adams CHAPTER 9 SEA LEVEL RISE AND THE SACO EstuarY: Tidal Marshes...105 by Michael Esty CHAPTER 10 Water QualitY IN THE SACO RIVER....................113 by Stephan I. Zeeman and Tyler Spillane iii Saco River Corridor Commission Biddeford-Saco Chamber of Commerce and Industry Town of Saco: Planning Board, Conservation Commission Saco Valley Land Trust Saco River Salmon Club S A C O Saco School District Saco Spirit 60 Fish Species Rumery’s Boat Yard B I D D E F O R D A Stewardship Network The Saco River estuary has Heart of Biddeford the highest number of fish Sustains the Saco Estuary species --including adult and Biddeford larval fish caught in the river and bay -- recorded in any School District Saco Water Biddeford Blandings Park Maine estuary. Wildlife Sanctuary Marston’s Marina 133 Bird Species About the Stewardship Network Many people care for the Saco Estuary. Together they form a Stewardship Network protecting water, wildlife Nearly half of all bird and habitats. Residents, visitors and businesses benefit species in Maine have from the efforts of the Stewardship Network. The surpris- been observed using Commission Coastal Waters ingly diverse collection of plants, birds and fish discov- the Saco River estuary. ered by UNE and Wells Reserve researchers is a conse- Many of the species are not commonly associated quence of the cumulative actions taken by these people with estuaries. to sustain the Saco Estuary and the values most important to the people who live work and play in the region. Saco Bay 360 Acres of Tidal Marsh 10 Rare Plants Tackle Camp Ellis Three types of tidal marshes --salt, A surprising diversity of plants brackish, and freshwater-- occur here. live in these marshes, including Pool Land Trust Biddeford These marshes improve water quality and ten species that are rare in Maine provide habitat for many kinds of wildlife. and/or nationally. This research is part of Maine’s Sustainability Solutions Initiative, a program of the Senator George J. Mitchell Center, which is supported by National Science University of New England MollyMaps 2014 Foundation award EPS-0904155 to Maine EPSCoR at the University of Maine. Town of Biddeford: Planning Board, Open Space Committee, Conservation Commission, Shellfish Committee Planning Board, of Biddeford: Town State of Maine: DEP, DMR, DIFW Wells National Estuarine Research Reserve Rachel Carson National Wildlife Refuge Friends of Wood Island Lighthouse Saco River Corridor Commission Biddeford-Saco Chamber of Commerce and Industry Town of Saco: Planning Board, Conservation Commission Saco Valley Land Trust Saco River Salmon Club S A C O Saco School District Saco Spirit 60 Fish Species Rumery’s Boat Yard B I D D E F O R D A Stewardship Network The Saco River estuary has Heart of Biddeford the highest number of fish Sustains the Saco Estuary species --including adult and Biddeford larval fish caught in the river and bay -- recorded in any School District Saco Water Biddeford Blandings Park Maine estuary. Wildlife Sanctuary Marston’s Marina 133 Bird Species About the Stewardship Network Many people care for the Saco Estuary. Together they form a Stewardship Network protecting water, wildlife Nearly half of all bird and habitats. Residents, visitors and businesses benefit species in Maine have from the efforts of the Stewardship Network. The surpris- been observed using Commission Coastal Waters ingly diverse collection of plants, birds and fish discov- the Saco River estuary. ered by UNE and Wells Reserve researchers is a conse- Many of the species are not commonly associated quence of the cumulative actions taken by these people with estuaries. to sustain the Saco Estuary and the values most important to the people who live work and play in the region. Saco Bay 360 Acres of Tidal Marsh 10 Rare Plants Tackle Camp Ellis Three types of tidal marshes --salt, A surprising diversity of plants brackish, and freshwater-- occur here. live in these marshes, including Pool Land Trust Biddeford These marshes improve water quality and ten species that are rare in Maine provide habitat for many kinds of wildlife. and/or nationally. This research is part of Maine’s Sustainability Solutions Initiative, a program of the Senator George J. Mitchell Center, which is supported by National Science University of New England MollyMaps 2014 Foundation award EPS-0904155 to Maine EPSCoR at the University of Maine. Town of Biddeford: Planning Board, Open Space Committee, Conservation Commission, Shellfish Committee Planning Board, of Biddeford: Town State of Maine: DEP, DMR, DIFW Wells National Estuarine Research Reserve Rachel Carson National Wildlife Refuge Friends of Wood Island Lighthouse CHAPTER 3 PLANTS OF THE SACO ESTUARY TIDAL MARSHES BY PAM MORGAN INTRODUCTION Tidal marshes are wetlands composed primarily of grasses, sedges and rushes that occupy the intertidal zone—the area between low and high tide. The Saco Estuary contains more than 350 acres of tidal marshes that vary from salt marshes near the mouth of the river, to brackish marshes, to tidal freshwater marshes in the estuary’s upper reaches near Cataract Dam. Why should we care about tidal marshes? Tidal marshes, some of the most productive habitats in the world, provide a home for a wide variety of plants and animals, including fish and birds. These habitats provide a diverse range of benefits—from aesthetics to fish habitat to water filtration. Many fish species use the surface of the marsh as a place to forage and escape from predators. In fact, tidal marshes are widely known as nursery grounds for important fish species. The fish and invertebrates of the marshes also provide an important source of food for resident and migratory birds, such as great blue herons and snowy egrets. People also value tidal marshes because they help clean coastal waters by extracting pollutants from water entering the estuary. Tidal marshes also serve as important buffer areas between developed coastal areas and the sea, absorbing the energy of incoming waves. In addition, marshes are valued highly for their beauty, which residents and visitors alike appreciate from the shore and from the water, making them an important recreational resource. One of the main reasons that scientists from the University of New England (UNE) and the Wells National Estuarine Research Reserve (NERR) have studied the Saco River tidal marshes is that very little was known about them. With this study, we now have a better understanding of the values these marshes provide and can monitor their health into the future. 17 18 CHAPTER 3 PLANTS OF THE SACO ESTUARY: Tidal Marshes What issues should we be concerned about? In many estuaries, tidal marshes are degrading and even disappearing due to a number of human-caused threats (Gedan et al. 2011). These threats include increased coastal development and associated pollutants (especially nitrogen), climate change and associated sea level rise, increased flooding events and invasive species. Phragmites australis, also known as the common reed, is one invasive species of particular concern in the Saco Estuary’s tidal marshes (Figure 1). This plant can quickly take over a marsh, choking out native plant species and decreasing its value as fish and bird habitat. Its dead stems have been known to catch fire, threatening nearby homes and businesses (Saltonstall 2005). Although the common reed provides some benefits to an estuary, its negative impacts have led scientists and land managers to develop a variety of methods to prevent its further spread (Saltonstall 2005). FIGURE 1 The invasive common reed, Phragmites australis. CHAPTER 3 PLANTS OF THE SACO ESTUARY: Tidal Marshes 19 STUDY OBJECTIVES—PLANTS Our objectives for the plant study were to answer these questions related to the tidal marshes: 1. What plants grow in the tidal marshes, and how do the plants change as one moves down the river? 2. How diverse are the plant communities in the marshes? 3. What rare and threatened plant species grow in the tidal marshes? 4.